1. Field of the Invention
The present invention relates to a static inverter. Static inverters are devices in which electrical energy is converted to electrical energy in another form through static or non-moving parts. In static inverters to which the present invention pertains, dc energy is converted to ac energy. The principal elements of such an inverter are an inductive means through which current is passed intermittently, and one or two electronic switches, typically transistors.
The invention has further application to the ballasting of gas discharge light sources in which a very high ignitiion voltage is required, current limiting is required during early warm-up, when the voltage is minimum, and ballasting is required during final run operation for stability.
2. Description of the Prior Art
Static inverters have been described in the U.S. Pat. Nos. 3,914,080; 4,002,999 of Hesler et al, and in the more recently filed applications of Peil, Ser. No. 875,337 (now refiled in a continuation-in-part as Ser. No. 028,405) and Ser. No. 909,300, all of which are assigned to the Assignee of the present application.
In the application Ser. No. 909,300, an inverter is disclosed employing a single blocking oscillator for operating a gas discharge lamp. An ignition pulse is provided by a separate circuit comprising an SCR switch. It is preferrable to achieve both the ignition and operating functions from a single circuit.